The BGS Lexicon of Named Rock Units — Result Details

Gouther Crag Breccia Member

Computer Code: GRCG Preferred Map Code: GrCg
Status Code: Full
Age range: Caradoc Series (O4) — Caradoc Series (O4)
Lithological Description: A massive, poorly sorted volcaniclastic breccia, comprising heterolithic volcanic clasts, including abundant pink-weathered rhyolite clasts.
Definition of Lower Boundary: The abrupt change from bedded volcaniclastic sandstone within the Mardale Sandstone Formation to volcaniclastic breccia.
Definition of Upper Boundary: Taken at the sharp base of the overlying thin unit of bedded volcaniclastic sandstone, which is succeeded by massive, weakly eutaxitic, dacitic lapilli-tuff.
Thickness: To 180m
Geographical Limits: Swindale, Cumbria, between Dry Grove Gill [NY 510 122] and Mullender [NY 522 132].
Parent Unit: Mardale Sandstone Formation (MRL)
Previous Name(s): Gouther Crag Member (-940)
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Area  Gouther Crag, 500m south of Truss Gap, Swindale, Cumbria. 
Reference(s):
Millward, D, 2002. Geology of the area between Haweswater and Shap. British Geological Survey Research Report RR/02/02 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E030 E039